The deputy president had left hours earlier for a campaign rally in the town of Kitale, where he joined President Uhuru Kenyatta.

Image copyrightReutersImage caption
Mr Ruto's home in Sugoi village near the city of Eldoret

Mr Kenyatta is seeking re-election next month.

While Kenya's 2013 elections passed relatively peacefully, there was serious post-election violence following the 2007 polls, which left more than 1,000 people dead and 600,000 displaced from their homes.

However, experts say they do not expect to see the same level of conflict following the 8 August vote.